1. Field of the Invention
The present invention is broadly concerned with an improved latching and actuator apparatus designed for use with high pressure gas cylinders typically used by patients suffering from respiratory diseases or other ailments, in order to greatly facilitate the needed gas therapy. More particularly, it is concerned with such a latching-actuator apparatus which includes a single operator which can be readily shifted by the user to accomplish all needed functions, including on-off gas flow operations and cylinder replacement.
2. Description of the Prior Art
Gas inhalation therapy has been used for many years as a beneficial treatment for many diseases. For example, oxygen therapy has long been prescribed by physicians for patients suffering from such ailments as chronic respiratory and heart diseases (e.g., emphysema, chronic bronchitis, angina, etc.). The oxygen or other gases used in this therapy can be bottled in disposable containers, or, more typically, in reusable high pressure cylinders. In the latter case, the cylinders are normally equipped with a connection yoke which is threadably secured to the cylinder, along with a valve operator and pressure regulator. In use, the patient opens the valve in order to permit gas flow from the cylinder, and, after the appropriate therapy, the valve is turned off. When the cylinder is depleted, however, it is generally necessary to have a fresh cylinder delivered and hooked up to the yoke and valve structure.
The foregoing procedures are in common use, but they present a number of significant problems. In the first place, many patients requiring gas therapy are very weak and lacking in dexterity, and therefore proper manipulation of the on-off valve associated with the gas cylinder can be difficult (it typically requires at least two and one-half foot-pounds of torque to operate the valve). For example, if the valve is not completely closed after use, the cylinder gas can be wasted, and the pressure regulator is subjected to the effects of continual pressure, something which should be avoided.
The operational problems associated with gas cylinder changeovers are even more acute than those involving the on-off valve. Indeed, the problems encountered in changing gas cylinders are so formidable that, almost universally, this operation must be done by a service technician. About eight foot-pounds of torque or more may be required to release and install a cylinder yoke, and these levels of torque can be difficult to achieve by many patients.
While most bedridden and convalescent patients requiring gas therapy make use of large, stationary cylinders of gas, so-called ambulatory units are also available for patients permitted more freedom of movement. Obviously, the gas cylinders used in the latter instances are much smaller than the large stationary cylinders. Nevertheless, the same general problems as outlined above plague ambulatory gas therapy devices as well. As a consequence, most ambulatory patients tend to purchase the largest possible portable gas cylinders, so as to minimize the need for returning to a dealer for changeover servicing by a technician. This of course presents problems to the ambulatory patient, in that the overall apparatus is rather large, heavy and bulky; but many patients prefer this rather than making repeated trips to the dealer for cylinder replacements.